10X three element eyepiece

ABSTRACT

A three element 10X eyepiece has an apparent field of view of about 52.3* and a maximum exit pupil diameter of 1.60mm.

United States Patent Shoemaker June 10, 1975 UN 10X THREE ELEMENTEYEPIECE [56] References Cited [75] Inventor: Arthur H. Shoemaker, WestAururu. UNITED STATES PATENTS N-Y- 1.759.529 5/l930 VanHofe 350/229 73A!" 1 A 0 t' 'l C t' I I bxlgncL g z fzg gzj orpora Ion PrimaryE,rarr1inerPaul A. Sacher Attorney. Agent, or FirmAlan H. Spencer;William Fllcdi ay I. I974 C. Neaion: H. R. Berkenstock .Ir.

[2!] App]. No.: 465,934

[57] ABSTRACT A three element 10X eyepiece has an apparent field of '4 r350/229 view of about 523 and a maxlmum exit pupil dlame- 581 Field ofSearch 350/229. 175 E of "60mm 3 Claims, 1 Drawing Figure 5 R5 53/:- VVAT3 R3 sa R2 1 TI l i PP X THREE ELEMENT EYEPIECE BACKGROUND OF THEINVENTION THE DRAWING FIG. I is an optical diagram of the eyepieceviewed Ill transverse to the optical axis. [5

DESCRIPTION OF THE INVENTION Referring to FIG. 1, an eyepiece X. isshown diagramatically with optically aligned lenses I. II and III. Thefirst element I is a concavo-convex positive singlet,

the second element is a double convex positive doublet and the thirdelement III is a eonvex-concavo positive singlet. The eyepiece has aPetzval radius of about l.42F and eye-relief of about 0.77F which isadequate for confortable viewing with or without eyeglasses.

The parameters of an eyepiece according to the present invention are setforth in Table with the axial thickness of successive lens elementsdesignated TI to T4, and the successive axial spaces from the eyepiecefocal plane FP to the observers eye designated S1 to S4. The successivelens radii are designated Rl to R7 where the minus sign applies tosurfaces whose center of curvature lies on the focal plane side of theirvertices. The refractive indices and Abbe numbers of the glasses in thesuccessive lenses are fixed absolute values designated ND( l) to ND(4),and 11(1) to 11(4) respectively.

It will be apparent that the foregoing absolute values are variabledepending on the value of F. Other forms are thus possible and changesmay be made in the values of the constructional data named on therelationships in the first of the above charts. without departing fromthe spirit of this invention.

What is claimed is:

l. A microscope eyepiece having a magnification of about 10X. anapparent field of view of about 52.3 and a maximum exit pupil diameterof about lbmm being well corrected for coma. astigmatism. distortion andcolor and having a focal length F and three lens elements aligned alongan optical axis extending from the focal plane of said eyepiece. whichcomprises a conca vo-convex positive singlet I as the first element. adouble convex positive doublet II as the second element and aconvex-concavo positive singlet III as the third element to provide aPetzval radius of 1.42F and eye relief of 0.77F.

2. The eyepiece according to claim 1 wherein said lens elements have thefollowing values:

TABLE I Refractive Abbe Lens Radius Thickness Space Index Number S=O.6782F R =6.7853F I T,=U.32IOF NDt I )=l.58800 u( l )=6l.l9

R ='I.47I()F S.,=o.oo40F R;,= 2.] IZOF T ==Ul3090F ND( '1 i=1 .5880011(2 )=6l l 9 II R l.9932F T 0. l 2H4F ND( 3 l=l .78600 I 3 F2552 R6.7853F s,,=o.oa4aF R,,= 0.839% III T =().24(l8F ND(4)=I.58800v(4)=6l.19

S =(].77Z5F l t a y Refractive Abbe ICCC I imer r f F Is the focallength of hi Lyep n ml" Lens Radius Thickness Space Index Number C Anembodiment of the present invention with a focal 5, length (F) of 24.9]9has the following values: R

(1.7853F l T]: ND( I I: VI 1 I: Lem Radius 'I'hicltncss Space 032 lllF I68800 6. I l9 R fi -two I.47HIF R.=-lhu.os4 .65 5 I T,=S.UIIU U.UU4UF R.-3h.h57 R3= u to 2.1mm;

Ill

and the axial thicknesses of successive lens elements are Tl tn T4,successive axial spaces fmm the eyepiece focal plane are S] to S4,successive lens radii are R] 10 R7, where the minus sign applies tosurfaces whose center 0f curvature lies on the focal plane side of theirvertices. refractive indices and Abbe numbers of the lenses are absolutefixed values ND( 1 to ND(4). and v( I l to 1 (4) respectively. and F isthe focal length in millimeters 3. The eyepiece according to claim 2wherein F is 24.)l9mm.

1. A microscope eyepiece having a magnification of about 10X, anapparent field of view of about 52.3* and a maximum exit pupil diameterof about 1.6mm, being well corrected for coma, astigmatism, distortionand color and having a focal length F and three lens elements alignedalong an optical axis extending from the focal plane of said eyepiece,which comprises a concavoconvex positive singlet I as the first element,a double convex positive doublet II as the second element and aconvex-concavo positive singlet III as the third element to provide aPetzval radius of 1.42F and eye relief of 0.77F.
 2. The eyepieceaccording to claim 1 wherein said lens elements have the followingvalues:
 3. The eyepiece according to claim 2 wherein F is 24.919mm.